﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _13.ZerosInFact
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Insert a positive integer number");
            int n = int.Parse(Console.ReadLine());

            int zeros = 0;

            for (int i = 5; i <= n; i *= 5)
            {
                int currentZeros = n / i;
                zeros += currentZeros;
            }

            Console.WriteLine(zeros); // TODO
        }
    }
}
